Changing Ph
Dora, An often overlooked (or unknown by the hobbyist) facet of the maintenance of aquarium filters, their materials and the substrate of the tank concerning the autotrophic nitrifying bacteria you refer to, and the “gunk” (mulm) — or more properly “sludge” as its found as a more compacted “yellow gook” in the filter is that while there are some nitrifying bacteria colonizing the surface of this sludge, internally this waste material is being colonized by heterotrophic bacteria which are anaerobic.
As opposed to our beneficial aerobic nitrifiers, these anaerobic bacteria are often harmful in additionally creating noxious gases such as methane, which is poisonous to the fish and depending upon the species of these heterotrophic bacteria they may occasionally revert the dissimilation (rather than denitrification) of these nitrogenous compounds converting nitrate to nitrite and finally into ammonia. For this reason alone, these materials should be removed from filters whenever observed and should NOT be allowed to accumulate; this bacteria’s harmful effects far outweighs any benefits the beneficial bacteria may offer and its non-productive in allowing beneficial bacteria to colonize this sludge.
Getting back to filters, materials and substrates, for best and most efficient employment of all of your nitrifying bacteria the surfaces of these sites should NEVER be allowed to build up any quantities of mulm (in this case it is considered “mulm”) and it should be kept to a minimum — not only to prevent the obvious reduction in water flow but to maintain your bacteria populations at their peak at all times - - and while reduced water flow equates to reduced oxygen to these bacteria there is an overlooked element that is not realized.
Most hobbyists are not aware of the detrimental effects to their nitrifying bacteria, of the build-up of mulm and debris in their filters and on the surfaces of their substrate. Since the Nitrospira and Nitrobacter (nitrite converting bacteria) are totally dependant on the productions of nitrite by the Nitrosomonas (ammonia converting bacteria) and while they are found in close proximety to these bacteria (populating the same surfaces), even though they will now be taking their nutrients out of the water column their (Nitrospira and Nitrobacter) physical closeness to the Nitrosomonas enables (and encourages) them to take direct advantage of the nitrites immediately being produced by these Nitrosomonas.
Not especially a bad thing — but when the bio-film is allowed to excessively build up, these Nitrospiras and Nitrobacters can multiply to the effect of overwhelming the Nitrosomonas, starving them of oxygen. This has the effect of reducing the amounts of ammonia being converted with the resultant starving out of the Nitrospiras and Nitrobacters of food. A dangerous and detrimental downward spiral takes effect. For this reason, while these surfaces do not need to be spotless, any build-up of mulm and/or the excessive build-up of their bio-film should be discouraged. Ray
Category: Philippines Internet Koi Society
